1. Field of the Invention
The present invention relates to beverages having a high concentration of non-polymer catechins.
2. Related Art
It is known that catechins are physiologically useful, having cholesterol-level-increase suppressing action (Japanese Patent No. 1620943) or α-amylase activity inhibitory action (Japanese Patent No. 3018013).
In order to allow catechins to exhibit such physiological effects, drinking of 4 to 5 cups of tea a day is necessary for an adult (The Food Industry, 35 (14), 26-30 (1992)). There is accordingly a demand for the development of a technique of incorporating catechins in a beverage at a high concentration, thereby enabling easier ingestion of a large amount of catechins.
Two methods for raising the concentration of catechins, which serve as an effective ingredient, in a beverage have been reported. One of the proposed methods is to add pulverized tea leaves (Japanese Patent Application Laid-Open No. Hei 10-234301). By incorporating pulverized tea leaves at a high concentration according to this method, however, the resulting beverage becomes too powdery, which damages smooth throat-feel and pleasant aftertaste. Moreover, since the resulting beverage is put on the market after going through preparation and distribution steps, the pulverized tea leaves as an effective ingredient are inevitably precipitated on the bottom of the container or floating on the surface of the beverage upon drinking. Particularly when a transparent package such as PET bottle is used, such a state having precipitates in the bottle greatly impairs its appearance and, in turn, the commodity value of the beverage. Upon drinking, the beverage bottle having a precipitate formed therein must be shaken or stirred in order to make the dispersion of pulverized tea leaves uniform.
The other method is to add catechins in the dissolved form by utilizing a concentrated green tea extract.
Since catechins in the dissolved form have a bitter or astringent taste, bitterness or astringency of a beverage containing a large amount of catechins becomes excessively strong. Bitterness or astringency upon drinking can be alleviated by the incorporation of a sweetener in the beverage, but some unpleasant taste derived from catechins remains after drinking and makes those who drink the resulting beverage uncomfortable. Accordingly, the beverage added with catechins in the dissolved form is not suited as a physiologically effective beverage which must be taken for long periods or daily.